Magic sensor

Using these probes, mages (and sorceresses) can detect magical anomalies. Geralt receives three of these magic sensors from Triss Merigold at beginning of Chapter III. They each must be placed in a specific location in order to triangulate on the coordinates of the magical anomaly.

One must be placed inside the "relief" on the back of the remaining standing wall of the ruined church in the centre of the cemetery.